The Importance Of Chalk Stream Restoration


With the water crisis intensifying around the world in line with climate change, more extreme weather events, population growth, ageing infrastructure and water mismanagement, the spotlight has turned once again on England’s chalk streams and the urgent need to protect and preserve these essential water resources for future generations.


As habitats, chalk streams are rare and valuable – and you’ll often hear them referred to as the rainforests of England. They’re essential for biodiversity, of course, but they’re also important water sources for drinking, as well as industry and agriculture.


Interestingly, 85 per cent of the world’s chalk streams can be found in England – but these freshwater resources are now being put under increasing pressure, with too much water being used and wasted, and excessive agricultural pollution taking place… which is driving a decline in biodiversity, as well as affecting water quality.


Another key issue is over-abstraction. Despite the fact that England – and the rest of the UK, in fact – is famed around the world for its damp climate and wet weather, recent levels of rainfall have not been sufficient to refill groundwater supplies so that chalk streams, rivers and other waterways see the summer water flow they’ve enjoyed in the past.


The south and east of England in particular are already experiencing water shortages in chalk streams and rivers, with the region now in line for drought conditions thanks to notably and/or exceptionally low rainfall compared to the long-term average.


Chalk streams are abundant in this part of the country and can be found everywhere from Dorset, Hampshire and Wiltshire to the Chilterns – and all the way up to Lincolnshire and Yorkshire.


The Chilterns Area of Outstanding Natural Beauty, for example, has nine significant chalk streams but many of these run dry for a lot of the year, while over 40 chalk streams can be found in Dorset and Hampshire… and given just how important water resources actually are, underpinning every aspect of human life, restoration of these waterways is only going to become more essential as time goes on.


What’s being done?


In October last year, the government launched its new chalk stream strategy, published by Catchment Based Approach’s Chalk Stream Restoration Group, which includes a series of recommendations to reduce pollution, eliminate over-abstraction and restore physical habitat and biodiversity.


Measures include flood water retention, reductions in nutrient and sediment inputs, drainage improvements for water meadows, pond creation for landscaping and water supply, water level control and natural flood management techniques, such as tree planting, to help reduce high river flows during intense and heavy rainfall.


One of the most iconic and quintessential chalk streams in England is the Hampshire Avon, which stretches across a large part of both Wiltshire and Hampshire.


In the last 20 years, the waterway has seen significant improvements in water quality, thanks to improved land use and management. Additionally, improvements have been seen in wastewater treatment, which has also helped reduce nutrient levels and improve fish habitat.


More recently, the Devils Brook chalk stream in Dorset has seen improvements in water quality and fish habitats, thanks to a two-year project led by the Farming Wildlife Advisory Group Southwest (FWAG).


The waterway rises in the chalk hills above the villages of Cheselbourne and Dewlish, serving as an important trout spawning and nursery stream.


Techniques designed to stop water flow have been implemented here, such as tree and hedge planting, new wetland areas, buffer strips and sediment traps. These measures have successfully reduced losses to the river and driven up water quality as a result.


Environment Agency Luke Kozak said: “By working with natural processes, the project has already improved riparian and in-stream habitat and water quality.  Our funding has been crucial in enabling FWAG to engage with partners and landowners, with some fantastic results and great examples of partnership working.


“We now hope to use our experiences gained from the Devils Brook project to improve chalk streams across Dorset.”


What are water suppliers doing?


In 2020, various water companies made a pledge to take steps to protect the nation’s chalk streams by reducing pollution rates and over-abstraction, with millions of pounds due to be invested.


Thames Water, for example, has committed to increasing the capacity of its Chesham sewage works by 30 per cent by 2023 so more wastewater can be stored and treated, reducing discharges into the river Chess.


The supplier has also pledged to stop groundwater and surface water infiltration into the sewers to prevent the network from being overwhelmed.


And all abstraction of water from Hawridge on the River Chess will be stopped entirely by the end of 2024, with £40 million in investments finding alternative water sources for the 12,000 people who currently source water from Hawridge.


Anglian Water, meanwhile, has devised a five-year programme with more than £800 million in investments included to protect chalk streams and deliver river restoration and support, habitat improvement, water treatment wetlands and phosphorus reduction.


It also intends to cap all major groundwater aquifers to recent actual levels to prevent deterioration, equating to a reduction of over 80 million litres a day – an industry leading position.


The water company also has plans in place to create up to 34 water treatment wetlands and carry out further investigations into 40 combined sewer overflows to see what environmental impact they’re having, implementing the necessary interventions for those considered to be the highest risk.


Businesses, too, have their part to play in protecting chalk streams around the country – and looking at how they can reduce their usage and consumption rates could make a significant difference.


There are various ways in which this can be achieved, whether that’s by focusing on water leak detection and water leak repair, finding new efficiencies in business operations or perhaps switching water supplier.


If you’d like to find out how to go about reducing your water footprint today, get in touch with the H2o Building Services team to discuss the options available.